Enhanced performance of chemical looping combustion of methane with FeO/AlO/TiO oxygen carrier.

Iron-based oxygen carriers supported on alumina or alumina/titania were prepared and evaluated for chemical looping combustion of methane. The reduction conversion of FeO/AlO and FeO/AlO/TiO particles was markedly increased with increasing inlet concentration and was slightly enhanced by elevated operating temperatures. According to the shrinking core model, the mass transfer coefficients ( ) of FeO/AlO and FeO/AlO/TiO reduction with methane are found to be 0.07 and 0.12 mm s. Complete combustion of methane is almost achieved for experiments conducted with FeO/AlO and FeO/AlO/TiO operated as the FeO/CH molar ratio reached about 5.4 and 4.4, respectively. Carbon deposition during methane combustion was avoided by using FeO/AlO/TiO as an oxygen carrier. More heat was generated for the combustion of methane by FeO/AlO/TiO oxygen carriers because methane more fully reacted with the FeO contained in the FeO/AlO/TiO oxygen carriers.